reverted ubuntu version to 22.04 for singularity tests

Author: tclose

.github/workflows/testsingularity.yml

@@ -14,7 +14,7 @@ concurrency:
 jobs:
   build:
     name: Build
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-22.04
     strategy:
       matrix:
         python-version: ['3.11', '3.12', '3.13']